Fig. 1.
The war impact on food prices in Poland – the ex-post errors (%) based on regARIMA models
| Period | 03.2022 | 06.2022 | 09.2022 | 12.2022 | 03.2023 | 06.2023 | 09.2023 | 12.2023 |
|---|---|---|---|---|---|---|---|---|
| Food (total) | 1.94 | 6.75 | 12.57 | 17.77 | 23.83 | 23.40 | 21.41 | 22.36 |
| Bread and cereals | 0.59 | 6.71 | 10.96 | 14.26 | 18.38 | 18.98 | 18.33 | 16.54 |
| Meat | 2.57 | 11.84 | 16.11 | 19.49 | 21.89 | 23.51 | 21.52 | 21.62 |
| Fish and seafood | 1.20 | 5.97 | 9.60 | 16.13 | 17.62 | 17.52 | 15.20 | 13.21 |
| Milk, cheese and eggs | 0.11 | 8.39 | 14.72 | 23.09 | 25.97 | 26.10 | 23.46 | 22.45 |
| Oils and fats | 1.70 | 13.27 | 19.42 | 23.27 | 18.41 | 12.35 | 4.99 | 5.43 |
| Fruits | 3.17 | −0.64 | 4.62 | 12.58 | 17.69 | 8.13 | 7.09 | 14.84 |
| Vegetables | 1.84 | 0.55 | 4.75 | 10.21 | 26.19 | 21.52 | 15.79 | 18.78 |
| Sugar et all | 1.52 | 6.11 | 17.60 | 22.37 | 27.44 | 31.16 | 30.52 | 30.51 |
Robustness check: the war impact on food prices in Poland – ex-post errors (%) from on Holt-Winters models
| Period | 03.2022 | 06.2022 | 09.2022 | 12.2022 | 03.2023 | 06.2023 | 09.2023 | 12.2023 |
|---|---|---|---|---|---|---|---|---|
| Food (total) | 1.33 | 4.51 | 11.49 | 16.00 | 21.06 | 18.84 | 18.35 | 18.57 |
| Bread and cereals | 0.31 | 5.53 | 9.31 | 11.69 | 14.89 | 14.26 | 13.13 | 10.49 |
| Meat | 4.52 | 14.50 | 19.13 | 22.72 | 24.79 | 27.00 | 25.19 | 25.44 |
| Fish and seafood | 0.91 | 5.76 | 10.58 | 15.80 | 16.86 | 17.14 | 16.23 | 12.98 |
| Milk, cheese and eggs | −0.21 | 7.17 | 14.55 | 23.21 | 26.61 | 25.10 | 23.45 | 22.64 |
| Oils and fats | 0.86 | 12.96 | 19.72 | 23.57 | 17.21 | 12.10 | 5.13 | 5.48 |
| Fruits | 1.47 | −3.88 | −1.51 | 9.29 | 13.34 | 2.78 | −0.72 | 9.77 |
| Vegetables | −0.71 | −4.47 | 0.60 | 9.45 | 20.93 | 13.45 | 9.74 | 16.01 |
| Sugar, et all | 0.32 | 0.70 | 12.65 | 18.62 | 23.14 | 22.22 | 22.85 | 24.32 |
Basic characteristics of regARIMA models used in ex-post prediction
| Specification | ARIMA model | Regressors (for outliers and shifts) | Standard error | Normality: Doornik-Hansen | Autocorrelation: Ljung-Box (12) |
|---|---|---|---|---|---|
| Food (total) | (1,1,0) | AO (1-2022), LS (6-2011) | 0.583 | 1.550 (p = 0.460) | 4.741 (p = 0.907) |
| (0,1,1) | |||||
| Bread and cereals | (1,1,0) | AO (1-2022), LS (9-2010), LS (3-2011) | 0.255 | 7.713 (p = 0.021) | 7.269 (p = 0.699) |
| (0,1,1) | |||||
| Meat | (0,1,2) | LS (12-2019), AO (2-2022), LS (4-2019), LS (5-2020) | 0.644 | 3.820 (p = 0.148) | 10.828 (p = 0.287) |
| (0,1,1) | |||||
| Fish and seafood | (0,2,1) | LS (12-2021), AO (1-2022), TC (11-2021), TC (12-2011), LS (11-2011), AO (3-2016) | 0.280 | 1.649 (p = 0.438) | 10.728 (p = 0.379) |
| (0,1,1) | |||||
| Milk, cheese and eggs | (1,1,0) | LS (11-2017), AO (1-2022), LS (3-2012), TC (4-2012), AO (12-2021) | 0.324 | 3.044 (p = 0.218) | 12.473 (p = 0.254) |
| (0,1,1) | |||||
| Oils and fats | (1,1,0) | TS (9-2021), LS (9-2021) | 1.031 | 28.462 (p = 0.000) | 19.735 (p = 0.032) |
| (0,1,1) | |||||
| Fruits | (0,1,1) | Easter[15] | 2.674 | 0.142 (p = 0.931) | 5.158 (p = 0.880) |
| (0,1,1) | |||||
| Vegetables | (0,1,0) | LS (6-2011) | 3.532 | 12.785 (p = 0.002) | 8.269 (p = 0.668) |
| (0,1,1) | |||||
| Sugar et all | (1,1,0) | LS (3-2011), TC (4-2011), TC (2-2011), LS (4-2014), TC (9-2010) | 0.511 | 2.821 (p = 0.244) | 5.648 (p = 0.843) |
| (0,1,1) |